Question

Explain the difference between a strong acid and a weak acid, using the two compounds below. Write chemical equations to support your answer. -HClO2(aq), a weak acid -HClO3 (aq), a strong acid

Answer 1

strong acid : it will completely ionise to give almost all H+ ions . its pH value is lower than weak acid.

       example : 0.1 M HCl is strong acid and H+ concentration is also 0.1 M

HCl --------------------> H+   + Cl-

weak acid : its ionisation always >100% . and its pH value is more than strong acid. which cannot give all H+ in the ionisation.

example : 0.1 M HF is weak acid and H+ ion concentration is not 0.1 M

HF <--------------------> H+   + F-

the acid strength depends on oxidation state of central element.

in HClO2 oxidation state of Cl = +3 so it is weak acid but in HClO3 , oxidation state of Cl is +5 so it is strong acid